Persecute (εδιωκον). Inchoative imperfect, "began to persecute" and kept it up. They took this occasion as one excuse (δια τουτο, because of this). They disliked Jesus when here first (John 2:18) and were suspicious of his popularity (John 4:1). Now they have cause for an open breach.

Because he did (οτ εποιε). Imperfect active, not just this one act, but he was becoming a regular Sabbath-breaker. The Pharisees will watch his conduct on the Sabbath henceforth (Mark 2:23; Mark 3:2).